docs: def split_class_dir_ratio(class_dir, output, ratio, seed):
      """Splits one very class folder
      """
      files = setup_files(class_dir, seed)
  
      split_train = int(ratio[0] * len(files))
      split_val = split_train + int(ratio[1] * len(files))
  
      li = split_files(files, split_train, split_val, len(ratio) == 3)
      copy_files(li, class_dir, output)